8.1 Characteristics of the Endocrine System Flashcards
How does the endocrine system transmit messages between different parts of the body?
They use chemical messengers called hormones.
Define hormones.
They are chemicals produced by endocrine cells, most of which are grouped together in glands knows as endocrine glands.
What happens to hormones?
They are released into the blood and carried through the circulatory system to affect the activity of one or more specific tissues in another part of the body.
What is a target organ?
An organ affected by the activity of a particular hormones is described as target hormone; one hormone might have several target organs.
Why does a hormone affect the activity of only its target organ, even though it encounters other body tissues as it circulates through the blood?
The cells of the target organ have receptors that specifically bind to their respective hormone.
What does the endocrine system include?
Endocrine glands, such as the thyroid, pituitary, and adrenal glands.
What organs have endocrine cells?
Pancreas, kidneys, ovaries, testes have endocrine cells aka endocrine functions.
What portion of the brain also produces a hormone?
Hypothalamus.
What happens upon receiving a stimulus?
An endocrine gland or endocrine tissue is induced to release a specific hormone into the bloodstream; hormone molecules are carried by the blood to target organs where they bind to specific receptors present in target cells to elicit a response.
What 2 main types of glands are present in the human body?
Endocrine glands and exocrine glands.
What is the function of an endocrine gland?
It’s a gland that secrets the chemicals (hormones) it produces directly into the bloodstream where they are carried to near or distant target organs.
What’s the function of exocrine gland?
It’s a gland that secrets the chemicals it produces through special ducts that empty into specific organs.
Describe endocrine gland.
Lack ducts and are considered ductless glands.
How do endocrine glands facilitate the entry of hormones into the blood?
they are richly vascularized.
Describe the pancreas.
It has both: endocrine and exocrine tissues. As part of the endocrine function, the pancreas secrete hormones, such as insulin and glucagon, into the bloodstream. As part if the exocrine function, the pancreas secretes pancreatic juice into small ducts that then join together and form a larger duct that eventually empties into the duodenum.
